The 21-year-old was sent out to Granada on loan last season and, in spite of suffering relegation, enjoyed an extremely productive nine months in Spain, making 37 appearances in total.
He was duly handed a place in the first team squad for pre-season and has impressed at both No.10 and as a deep-lying midfielder.
And Pereira, looking ahead to next season, made it clear that he could serve as an important factotum for the Portuguese next season.
“I’ve come back and I feel calm, I feel stronger mentally and physically,” said Pereira.
“I can play as a midfielder, as a winger, as a holding midfielder. I’ll play wherever the manager plays me but my best position is as a (central) No. 6, eight or 10.”
The problem with Pereira prior to his loan spell in Spain was that, realistically, his favoured No.10 role would never be vacant in the first team, leaving him to squabble for a just as improbable place out wide.
But he has returned to Old Trafford bringing something new to the table. The Brazilian has gone from a promising attacking midfielder to something of an all-round utility man, blessed with skill and a capacity for graft in equal measure, which could probe crucial when Mourinho decides he chooses to accommodate in the first team over the next few weeks.